酵母菌处理系统中氮缺乏引起的污泥膨胀控制

研究了酵母菌处理色拉油加工废水系统中投加氮源对处理效果的影响及对污泥膨胀的恢复作用批量实验结果表明:①添加氮源有助于提高去除效果,碳氮比(COD/N)为50/1～20/1的条件下,油去除率最高,达90%以上;②添加氮源能够改善污泥沉降性,COD/N比为50/1、20/1时污泥沉降性明显优于100/1、200/1和不加氮的条件.连续试验中按COD/N为20/1添加氮源,污泥体积指数(SVI)稳定在100～200,油和COD去除率分别达95%和90%以上.氮缺乏色拉油加工废水中添加氮源是控制污泥膨胀的有效方法之一.     

酚类化合物雌激素效应的比较研究

采用重组人雌激素受体基因片段(hER)及共激活因子(GRIP1)双杂交酵母检测体系,检测9种酚类物质的类雌激素和抗雌激素效应.结果表明,所检测的化合物中有3种同时表现出雌激素诱导与抑制活性;2种只表现出雌激素诱导活性;1种只表现出雌激素抑制活性;3种均没有雌激素诱导与抑制活性.结构分析表明:酚类中产生雌激素活性的物质具有取代基位于对位且邻位没有大的取代基团的结构;烷基在对位的酚类物质也能显示出雌激素拮抗活性.所采用的双杂交酵母检测体系适用于外源物质的雌激素活性检测,具有较高的灵敏度;结合外源物的雌激素诱导与抑制活性,用于分析污染物的体内作用方式.     

酵母菌生物膜-水解酸化-BAF组合工艺处理高浓度三元驱废水

采用酵母菌生物膜-水解酸化-BAF生物组合工艺处理油田高浓度三元驱废水。实验结果表明:酵母菌生物膜具有降解污染物和调节水质的双重作用,可保障后续生物处理工艺的稳定运行。酵母菌生物膜、水解酸化及二级BAF的最佳HRT分别为18,12,36 h。工艺连续运行25 d,生物组合工艺对废水黏度、HPAM及COD去除率分别为80%、40%和69%。处理后出水ρ(石油类)<1 mg/L,ρ(SS)<5 mg/L,中位粒径<0.3μm,出水水质可达SY/T 5329—2012《碎屑岩油藏注水水质推荐指标及分析方法》回注标准。     

酵母菌处理皂素生产废水的研究

通过小型批量试验 ,对酵母菌处理皂素生产废水的技术条件进行了研究。结果表明 :在pH为 5 .0 ,温度 30℃ ,处理时间 4 8h ,接种量 10 %的条件下 ,废水CODCr去除率可达 70 %。该技术操作简单 ,可作为预处理应用于实际工程中 ,并可回收一定的酵母蛋白 ,具有一定的经济效益     

不同pH条件下酵母菌处理高含油废水的研究

在使用混合酵母菌菌株处理高浓度含油废水中，研究了序批式反应器（SBR）内酵母菌在不同起始pH条件下对废水的处理效果。通过与pH中性或碱性条件比较发现，pH4～5的条件在酵母菌的发泡抑制、菌体生长以及COD／油去除等方面均显示出更好的效果，pH5是系统运行的最佳条件。长达100d的SBR连续运行试验表明，系统可以在pH=5条件下长期、稳定运行。     

固定化啤酒酵母制剂去除水中重金属离子

研究了天津某啤酒厂啤酒酵母废菌丝制备的生物吸附剂对水中重金属Cu2+、Zn2+和Cd2+的吸附作用;另外,为了增加其实用性,对海藻酸盐固定化啤酒酵母制剂去除重金属的效果及洗脱再生条件进行了研究。结果明,啤酒酵母制剂有较好的吸附能力,5 min就可以达到很高的吸附效率。Langmuir方程可对Cu2+、Zn2+和Cd2+的等温吸附过程进行很好的描述。当pH为5～6时,Cd2+、Zd2+和Cd2+的吸附效率最大,上除率在90％以上。啤酒酵母制剂固定化后,对Cu2+的最大理论吸附量达到15．74 mg/g。用HCl可对固定化制剂进行洗脱和再生。     

应用酵母菌处理木薯酒精废液的试验研究

应用酵母菌对木薯酒精废液进行了小型批量的处理试验研究.结果表明,该菌种对于高浓度有机废水具有很强的适应能力,能迅速形成优势菌群,分解有机物.在进水pH 5.0～5.5、温度30℃、曝气时间72 h、接种量1‰(v/v,活菌数为4.1×106个/mL)、溶解氧2～3 mg/L、BOD5∶N∶P为400∶2∶1条件下,COD和BOD5去除率可分别达85%和92%.该技术操作简单,可作为木薯酒精废液的一级生物处理,并可回收利用酵母蛋白.     

A Biomimetic Approach to the Detection and Identification of Estrogen Receptor Agonists in Surface Waters Using Semipermeable Membrane Devices (SPMDs) and Bioassay-Directed Chemical Analysis (12 pp)

Goal, Scope and Background Some anthropogenic pollutants posses the capacity to disrupt endogenous control of developmental and reproductive processes in aquatic biota by activating estrogen receptors. Many anthropogenic estrogen receptor agonists (ERAs) are hydrophobic and will therefore readily partition into the abiotic organic carbon phases present in natural waters. This partitioning process effectively reduces the proportion of ERAs readily available for bioconcentration by aquatic biota. Results from some studies have suggested that for many aquatic species, bioconcentration of the freely-dissolved fraction may be the principal route of uptake for hydrophobic pollutants with logarithm n-octanol/water partition coefficient (log Kow) values less than approximately 6.0, which includes the majority of known anthropogenic ERAs. The detection and identification of freely-dissolved readily bioconcentratable ERAs is therefore an important aspect of exposure and risk assessment. However, most studies use conventional techniques to sample total ERA concentrations and in doing so frequently fail to account for bioconcentration of the freely-dissolved fraction. The aim of the current study was to couple the biomimetic sampling properties of semipermeable membrane devices (SPMDs) to a bioassay-directed chemical analysis (BDCA) scheme for the detection and identification of readily bioconcentratable ERAs in surface waters. Methods SPMDs were constructed and deployed at a number of sites in Germany and the UK. Following the dialytic recovery of target compounds and size exclusion chromatographic clean-up, SPMD samples were fractionated using a reverse-phase HPLC method calibrated to provide an estimation of target analyte log Kow. A portion of each HPLC fraction was then subjected to the yeast estrogen screen (YES) to determine estrogenic potential. Results were plotted in the form of 'estrograms' which displayed profiles of estrogenic potential as a function of HPLC retention time (i.e. hydrophobicity) for each of the samples. Where significant activity was elicited in the YES, the remaining portion of the respective active fraction was subjected to GC-MS analysis in an attempt to identify the ERAs present. Results and Discussion Estrograms from each of the field samples showed that readily bioconcentratable ERAs were present at each of the sampling sites. Estimated log Kow values for the various active fractions ranged from 1.92 to 8.63. For some samples, estrogenic potential was associated with a relatively narrow range of log Kow values whilst in others estrogenic potential was more widely distributed across the respective estrograms. ERAs identified in active fractions included some benzophenones, various nonylphenol isomers, benzyl butyl phthalate, dehydroabietic acid, sitosterol, 3-(4-methylbenzylidine)camphor (4-MBC) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin (AHTN). Other tentatively identified compounds which may have contributed to the observed YES activity included various polycyclic aromatic hydrocarbons (PAHs) and their alkylated derivatives, methylated benzylphenols, various alkylphenols and dialkylphenols. However, potential ERAs present in some active fractions remain unidentified. Conclusions and Outlook Our results show that SPMD-YES-based BDCA can be used to detect and identify readily bioconcentratable ERAs in surface waters. As such, this biomimetic approach can be employed as an alternative to conventional methodologies to provide investigators with a more environmentally relevant insight into the distribution and identity of ERAs in surface waters. The use of alternative bioassays also has the potential to expand SPMD-based BDCA to include a wide range of toxicological endpoints. Improvements to the analytical methodology used to identify ERAs or other target compounds in active fractions in the current study could greatly enhance the applicability of the methodology to risk assessment and monitoring programmes.     

典型生活污水处理工艺对雌激素效应的去除

针对水环境中内分泌干扰物低浓度、高风险的特点,采用酵母菌法和酶联免疫法对3个污水处理工艺流程中污水的雌激素活性和雌二醇(E2)水平进行评价.结果表明,污水厂进水的雌二醇当量(EEQ)和E2的水平分别为4.35~7.58 ng·L~(-1)和36.95~83.43 ng·L~(-1).雌激素活性和E2的去除主要发生在生物处理阶段,如氧化沟、A~2/O和A~2/O+MBR工艺,且经以上工艺处理之后,雌激素活性和E2分别降低71.10%~75.54%和75.88%~80.72%.污泥对雌激素效应具有一定的去除作用,通过吸附作用污泥的EEQ和E2的含量分别为1.84~2.43 ng·g~(-1)和8.45~12.84 ng·g~(-1).但污水厂出水仍具有较高的雌激素活性,其EEQ为1.06~2.19 ng·L~(-1),对受纳水体的水生生物具有潜在的危害.酶联免疫法与酵母菌法具有很好的一致性,并为水环境雌激素的快速筛选和评价提供了一个新方法.     

Characterization of isolated yeast growth response to methionine analogs

Methionine is one of the first limiting amino acids in poultry nutrition. The use of methionine-rich natural feed ingredients, such as soybean meal or rapeseed meal may lead to negative environmental consequences. Amino acid supplementation leads to reduced use of protein-rich ingredients. The objectives of this study were isolation of potentially high content methionine-containing yeasts, quantification of methionine content in yeasts and their respective growth response to methionine analogs. Minimal medium was used as the selection medium and the isolation medium of methionine-producing yeasts from yeast collection and environmental samples, respectively. Two yeasts previously collected along with six additional strains isolated from Caucasian kefir grains, air-trapped, cantaloupe, and three soil samples could grow on minimal medium. Only two of the newly isolated strains, K1 and C1, grew in minimal medium supplied with either methionine analogs ethionine or norleucine at 0.5% (w/v). Based on large subunit rRNA sequences, these isolated strains were identified as Pichia udriavzevii/Issatchenkia orientalis. P. kudriavzevii/I. orentalis is a generally recognized as a safe organism. In addition, methionine produced by K1 and C1 yeast hydrolysate yielded 1.3 ± 0.01 and 1.1 ± 0.01 mg g^?1 dry cell. Yeast strain K1 may be suitable as a potential source of methionine for dietary supplements in organic poultry feed but may require growth conditions to further increase their methionine content.